#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>

int main()
{
    int max = 0, i,num;
    
    for (i = 0; i < 4; i++)
    {
        scanf("%d", &num);
        if (num > max)
            max = num;
    }
    printf("%d", max);
    return 0;
}